Fast redshift clustering with the Baire (ultra) metric. / Murtagh, Fionn; Contreras, Pedro.

2011. Paper presented at Science Image in Action - 7th International Workshop Data Analysis in Astronomy "Vito Di Gesu and Livio Scarsi", Erice, Italy.

Research output: Contribution to conferencePaper

Published

Abstract

The Baire metric induces an ultrametric on a dataset and is of linear computational complexity, contrasted with the standard quadratic time agglomerative hierarchical clustering algorithm. We apply the Baire distance to spectrometric and photometric redshifts from the Sloan Digital Sky Survey using, in this work, about half a million astronomical objects. We want to know how well the (more cos\ tly to determine) spectrometric redshifts can predict the (more easily obtained) photometric redshifts, i.e. we seek to regress the spectrometric on the photometric redshifts, and we develop a clusterwise nearest neighbor regression procedure for this.
Original languageEnglish
Publication statusPublished - 20 Apr 2011
EventScience Image in Action - 7th International Workshop Data Analysis in Astronomy "Vito Di Gesu and Livio Scarsi" - Erice, Italy
Duration: 16 Apr 201120 Apr 2011

Conference

ConferenceScience Image in Action - 7th International Workshop Data Analysis in Astronomy "Vito Di Gesu and Livio Scarsi"
CountryItaly
CityErice
Period16/04/1120/04/11

ID: 1436338